What do Manuka Honey Ratings Mean? (2026)
Information in this article shouldn't be considered medical advice. If you are considering taking manuka honey, propolis, royal jelly or bee pollen for their health benefits and are currently taking medication, please consult your doctor first.
What is Mānuka Honey?
Manuka honey is a floral honey produced by honeybees collecting nectar from the flowers of the manuka tree (Leptospermum scoparium).
This tree is unique to New Zealand with some distant relative species in Australia, however the internationally recognised definition of manuka honey is tied to New Zealand’s origin and testing standards.
Jars of manuka honey can be either multi-floral blends or mono-floral. Multi-floral manuka honey is made from manuka nectar and some nectar types from other flowers that are blended. Mono-floral manuka honey is made predominantly from manuka nectar. For a batch of honey to be mono-floral, the manuka honey must meet specific criteria in testing to ensure that manuka nectar is the dominant source. In New Zealand, these standards are defined and enforced through government-regulated testing.
Manuka honey is highly valued because it contains naturally occurring compounds that are present in much higher and more consistent levels than other honey types.
Where Genuine Mānuka Honey Comes From
Genuine New Zealand manuka honey must be produced and harvested in New Zealand, using honey made by Bees collecting nectar from Leptospermum scoparium. This point of origin is important as New Zealand applies a formal, legal definition for manuka honey. New Zealand origin manuka honey can be sold in bulk overseas for local packing however there are restrictions on how this is labelled and subsequently distributed and it is difficult to demonstrate authenticity of the honey once it is out of New Zealand.
The Ministry for Primary Industries (MPI) requires that honey is being labelled and sold as mono-floral manuka honey, must pass a set of chemical and DNA marker tests. These include specific compounds that confirm how much manuka nectar is in the honey, along with compound stability, and shelf-life.
Meanwhile honey produced outside of New Zealand comes from distantly related Leptospermum species, but is not subject to the same rigorous definition and testing framework. As a result, the term “manuka honey” only has a specific regulatory meaning in the New Zealand context.
Why New Zealand Formalised a Definition
New Zealand introduced a formal definition for manuka honey to address growing global demand, ensure consistent product quality, and to address the widespread misuse of the name. Prior to regulation, the term was often applied inconsistently and fraudulently including honey with minimal or no manuka content, which still happens in some international markets today.
The MPI definition includes five attributes that must be present for Honey to be classified as mono-floral and multifloral manuka honey. This definition was designed to protect consumers, support traceability, and ensure the honeys labelled all meet measurable and verifiable criteria.
Why is Mānuka Honey Unique?
The uniqueness of manuka honey lies in its chemical profile rather than just its appearance and taste alone. While many honeys do contain antibacterial components such as hydrogen peroxide, manuka honey is most notable for its high levels of non-peroxide activity.
This activity is largely associated with compounds that originate from manuka tree nectar that are concentrated during honey production and maturation. These compounds are not added artificially or enhanced after harvesting as they only occur naturally through the interactions between nectar chemistry, enzymes, and time.
Because of these maturing compounds and rigorous testing, manuka honey is distinct because it can be measured and categorised in ways that most other honeys cannot.
What Makes Mānuka Honey “Active”?
The term “active” is commonly used to describe honeys that contain antibacterial activity over and above what is caused by hydrogen peroxide alone. In the case of manuka honey, this activity is referred to as non-peroxide activity.
This non-peroxide activity is linked to methylglyoxal (MGO), the compound in manuka honey responsible for it renowned health-supporting ability, which is formed from dihydroxyacetone (DHA) naturally present in manuka nectar. Over time, DHA converts to MGO as the honey matures.
“Active” is not a regulated term by itself, though some honey companies do try to use it like one. This term cannot be used to accurately determine the potency of the honey.
Historical and Modern Measurement Context
Historically, “activity” was accessed using biological assays that measured the inhibition of bacterial growth. While these methods did indeed demonstrate activity, they are too variable and difficult to standardise at a large scale.
Modern manuka honey testing focuses on measuring chemical markers such as MGO and leptosperin within the honey, which provide more consistent and reproducible measured results. These markers allow activity to be quantified, compared, and audited through laboratory analysis rather than just observational testing.
UMF and MGO Explained Simply
“UMF” stand for “Unique Mānuka Factor”. It is a grading system system developed in New Zealand by the Unique Mānuka Factor Honey Association that measures and verifies the key markers associated with manuka honey including: MGO, leptosperin, DHA, and HMF. UMF ratings are expressed as numbers such as UMF 5+, UMF 10+, UMF 20+ to describe progressively more potent jars of manuka honey.
MGO refers specifically to the concentration of methylglyoxal which is measured in milligrams per kilogram. An MGO number, such as MGO 263+ or MGO 514+, indicated the minimum amount of methylglyoxal present at the time of testing.
While UMF and MGO are related, they are not identical. MGO measures one compound, while UMF reflects the overall profile of the honey including authentication markers. Both systems are used in New Zealand, but they provide different types of information.
- UMF 5+ = MGO 83
- UMF 10+ = MGO 261
- UMF 15+ = MGO 512
- UMF 20+ = MGO 826
- UMF 22+ = MGO 1000
- UMF 24+ = MGO 1120
- UMF 35+ = MGO 2190
Why Both Systems Exist
MGO values are straightforward and easy to interpret when comparing honeys as they represent a single, measurable compound. UMF ratings incorporate MGO alongside additional markers to confirm floral origin and reduce the risk of mislabelling.
As a result, many honey brands will display both on their labels, however still many only display the MGO value. Understanding the distinction helps avoid assuming that different label numbers are directly interchangeable.
Why Manuka Honey Potency Levels Differ
The potency levels in manuka honey can vary greatly, which is due to natural factors rather than processing choices. The amount of DHA in manuka nectar can differ greatly depending on factors such as: plant genetics, location, climate, and seasonal conditions.
After harvesting, the conversion of DHA to MGO within the honey continues over time. Storage temperature and age can influence this process, which is why honey is typically tested multiple times during maturation and before packing.
Higher MGO numbers do not necessarily indicate freshness or taste preference. They simply indicate measured concentrations of specific compounds at a certain point in time.
How to Read a Mānuka Honey Label
A manuka honey label should clearly state a few things:
- The UMF rating (if this is present there should also be a UMFHA license number somewhere on the label)
- The MGO value
- Some statement that the product originated from New Zealand.
In New Zealand, all honeys much have a batch number on them, and many credible labels provide ways to check the batch testing results or traceability.
Terms such as “raw”, “natural”, or “pure” are not unique to manuka honey and do not confirm authenticity or activity levels. Understanding the official grading markers is more informative than relying on descriptive language.
What Ratings Do Not Indicate
Potency ratings do not indicate flavour profile, texture, colour, or freshness. These can all vary based on the location and seasonal conditions the honey was produced and harvest in, along with the type of filtering, processing, or creaming processes were used during production. Two jars of honey with the same grade and from the same company, but harvested from different locations, could have very different colours and textures.
